1. Field of the Invention
The present invention relates to devices for switching power in microwave ovens. More specifically, the invention relates to devices for controlling the output power of the microwave oven's magnetron which involves a timer switch device.
2. Related Art
Generally, microwave ovens are required to change their operational modes because the necessary cooking period and the nature of the microwave cooking should be made different according to the properties of the food to be cooked. In known systems, separate timer switches having on and off functions as well as intermittent on and off states of electric power supplies for controlling the magnetron output power have been employed.
When either the "high position" (which is traditionally the condition of continuous electric power) or the "low position" (which is traditionally the condition of intermittent electric power) for each predetermined period are required, two large and expensive timer switches have been used for controlling the magnetron's output power. The use of two timer switches has the disadvantages of occupying a large volume of space, decreasing cost-effectiveness due to the complexity of the structure, and increasing manufacturing cost.